Capital Letters

While all the text displayed is in capital letters only, in the US version of the game it is in fact stored in mixed case ASCII. There is a hidden switch to enable the use of small letters, by using the Gameshark code 00000DCD. This also makes it the first game to spell Pokémon as Pokémon and not POKéMON, at least internally. The European versions, however, have all their text stored in upper case only.

Unused Room

To do:Screenshot?

There is also an unused room located behind the duel room in Challenge Hall. It resembles some sort of storage room, and the doors may have led to it earlier in development. All that remains is a basic layout.

In-Game Debug Menu

Screenshot of the debug menu visible in the start menu.

The main debug menu was accessed from the in-game start menu. While the menu at 04:43D2 was commented out before release—as evident by a single ret—at least the look of it can be recovered by using the following Game Genie Codes:

Japanese

North American

European

Text ID

35D-9BB-3BA

10D-9BB-D52

4EC-2CB-D5F

Size

10D-98B-D52

3ED-9EB-19E

10C-29B-D52

7 Items

07D-A1B-F72

067-7CB-F7E

07C-32B-F72

Cancel on Item 7

067-76B-F7E

07D-A4B-F72

067-7CB-F7E

Startup Debug Menu

There is also a start-up debug menu. While it can also be called in-game (since it has a quit option), the actual game boots using this menu's sub-routine. Use the following codes to activate it:

Japanese

North American

European

5B0-25B-C45

610-31B-A2D

640-36B-7FF

EF0-35B-917

USA

Europe

Since the European versions are multi-language, you will have to either have a save game with the language set, or you will have to skip the menu the first time around, since it will display the wrong (gibberish) string, because the game doesn't default to any language when confronted with an invalid language setting. It's notable that in all versions, all options of this menu have been translated.

Power On

This will boot the game regularly.

Duel Mode

This switches between the two duel modes.

Continue from Diary

This option will skip the title screen and directly put you where you last saved. If you don't have a save game yet, this will start a new adventure.

CGB Test

This test seems to be gone for good. It calls a single ret. Judging from the name, this option was there to test various color features.

SGB Frame

This test SGB Frame shows the using palettes and a dash grid over the whole screen to mark tile boundaries.

Standard BG character

This will show BG tiles 0x8800–0x97F0 on the screen.

Language

This will show the standard language menu, either English-German-French or English-Spanish-Italian, depending on the version of the game.

Look at Sprites

This option will start a sprite viewer.

Navigation: A will change the animation of the currently displayed sprite. Left/Right will de-/increase the sprite number. Up/Down will de-/increase the sprite number by 0x10. Select cancels the menu.

V Effect

This test is also gone. It calls a single ret. Judging from the name, this option might have tested hdma effects or vertical windowing effects (as used in the credits).

Create Booster Pack

This menu allows one to generate random booster packs. This was possibly done to check if the random seed tables were correct and correct sets of cards were generated.

Credits

This will play the whole credits.

Quit

This option will quit the menu. If the menu was called from the boot-up code, it will reboot the game and then display this menu again. Else, it will work as expected.

Build Dates

Unused Super Game Boy Borders

To do:See if the orange palette exists for all borders including every medal variation

There are two unused Super Game Boy borders that can be accessed from the debug menu. Game Genie code CA1-7FB-D5D will keep the selected initial border throughout the game. Turn on after the selected border is displayed or the initial border will be absent.

Unused Super Game Boy Border 1

An alternate palette likely leftover from testing from when they were deciding what palette to use. Game Genie code 020-1FB-E6A will load this border at startup.

Unused Super Game Boy Border 2

Used for testing border coordinates and palette usage. All palettes that were loaded into the SNES's VRAM while the border is loading will display on the SGB section of the border. Game Genie code 030-1FB-E6A will load this border at startup.

Regional Differences

Intro Boosters

Japanese

International

The images of the boosters that appear during the intro were changed outside of Japan to reflect the appearance of those distributed in the relative region.

Title Screen

Japanese

International

SGB Border

Japanese

International

The Japanese SGB border has writing on the PokéBall outline, which was removed from all subsequent releases abroad.

Card's back

Japan

International

The back of the cards was changed outside of Japan to reflect the appearance of the cards distributed abroad.

Jynx

Japan

International

Jynx's Lv. 23 design was revised to be purple rather than black in International versions, due to unfortunate similarities to the blackface stereotype.

Virtual Console Changes

The 3DS Virtual Console version does not emulate the Game Boy Color infrared hardware, leaving Mew Lv15 and Venusaur Lv64 unobtainable via Card Pop! and no way to assemble the Mysterious Pokémon Deck from the Pokémon Dome deck machine. Due to Card Popǃ being disabled, a bookcase in Ishihara's House cannot be interacted with as it refers to the "Phantom Cards" from using Card Popǃ. In addition, trying to interact with the Clerks at each Club for the Battle Center and the Gift Center will act as if the Clerks are not present, due to the game disabling the Battle Mode and the Trade Mode as all Game Link Cable features are neither supported nor emulated. Furthermore, since the Game Boy Printer cannot be used, the "Print" function from the PC has been disabled, the only change that is directly mentioned in the manual for the game. Also, because the game is locked in Game Boy Color mode, it cannot be played in monochrome Game Boy mode or with its Super Game Boy borders.

Jynx

Original (Int)

Virtual Console

As with Pokémon Snap, Jynx Lv23 has been altered to closer match the modern design of the Pokémon. Jynx's face, hands, and the background were changed from dark purple to light purple.